Title: Systematic characterization of degas-driven flow for poly(dimethylsiloxane) microfluidic devices

Abstract

Degas-driven flow is a novel phenomenon used to propel fluids in poly(dimethylsiloxane) (PDMS)-based microfluidic devices without requiring any external power. This method takes advantage of the inherently high porosity and air solubility of PDMS by removing air molecules from the bulk PDMS before initiating the flow. The dynamics of degas-driven flow are dependent on the channel and device geometries and are highly sensitive to temporal parameters. These dependencies have not been fully characterized, hindering broad use of degas-driven flow as a microfluidic pumping mechanism. Here, we characterize, for the first time, the effect of various parameters on the dynamics of degas-driven flow, including channel geometry, PDMS thickness, PDMS exposure area, vacuum degassing time, and idle time at atmospheric pressure before loading. We investigate the effect of these parameters on flow velocity as well as channel fill time for the degas-driven flow process. Using our devices, we achieved reproducible flow with a standard deviation of less than 8% for flow velocity, as well as maximum flow rates of up to 3 nL/s and mean flow rates of approximately 1-1.5 nL/s. Parameters such as channel surface area and PDMS chip exposure area were found to have negligible impact on degas-driven flow dynamics,more » whereas channel cross-sectional area, degas time, PDMS thickness, and idle time were found to have a larger impact. In addition, we develop a physical model that can predict mean flow velocities within 6% of experimental values and can be used as a tool for future design of PDMS-based microfluidic devices that utilize degas-driven flow.« less

Authors:

Liang, David Y. ^[1]; Tentori, Augusto M. ^[1]; Dimov, Ivan K. ^[2]; Lee, Luke P. ^[1]

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+ Show Author Affiliations

1. Univ. of California, Berkeley, CA (United States) Biomolecular Nanotechnology Center, Berkeley Sensor and Actuator Center
2. Univ. of California, Berkeley, CA (United States) Biomolecular Nanotechnology Center, Berkeley Sensor and Actuator Center; Univ. de Valapariso, Valapariso (Chile)

Publication Date:

Sat Jan 01 00:00:00 EST 2011

Research Org.:

Univ. of California, Berkeley, CA (United States) Biomolecular Nanotechnology Center, Berkeley Sensor and Actuator Center

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1076495

Grant/Contract Number:  

AC05-06OR23100

Resource Type:

Accepted Manuscript

Journal Name:

Biomicrofluidics

Additional Journal Information:

Journal Volume: 5; Journal Issue: 2; Journal ID: ISSN 1932-1058

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING